An emission reduction device which may be removably affixed to a diesel engine's exhaust system. The device comprises an outer casing which may be divided into a lower portion and an upper portion, the lower portion of which is removably attachable to the exhaust system of a diesel engine; a carcass for holding a bobbin wherein the carcass is attached to the lower portion of the outer casing at the point where the exhaust enters the outer casing and the carcass has a beveled opening in a diagonal line in its proximal part and a bobbin positioned in its distal part; one or more fibrous blanket cylinders; and a guide for arranging and securing the one or more fibrous blanket cylinders within the outer casing. The fibrous blanket cylinders may be wrapped in a wire mesh. In an alternative embodiment, a second fibrous blanket formed into a cone with the larger diameter of the cone positioned proximally may be removably inserted in the carcass.